1. Field of the Invention
The present invention relates to a method for protecting and preventing corrosion on the surface of metal coils during storage. More particularly, the present invention relates to a method and package employing vapor phase corrosion inhibitor impregnated materials for wrapping and storing metal coils in an eye horizontal position.
2. Background Art
In metal manufacturing it is common practice to form ingots of metal, which are subsequently rolled into long, relatively thin sheets. The sheets are typically then rolled into coils so that the long thin sheets of metal are easy to transport through the manufacturing facility and eventually to finished goods fabricating plants. The coils of metal have an opening in the middle, which is typically referred to as the xe2x80x9ceyexe2x80x9d of the coil.
The coils of metal can be transported in two different orientations. The coil can be turned on its side such that the eye is perpendicular to the floor. This is referred to as the xe2x80x9ceye to the skyxe2x80x9d orientation. In the eye to the sky orientation, the metal coil is typically placed on a pallet and moved from place to place with a forklift. The eye to the sky orientation is not always desirable for several reasons. First, when the metal coil is to be uncoiled for use, it must be set back on its side, such that it rests on the surface of the coil in what is termed the xe2x80x9ceye horizontalxe2x80x9d position. Secondly, the eye to the sky orientation does not make efficient use of space during transportation and storage. Lastly, moving the metal coils by forklift is not efficient in a manufacturing environment.
The eye horizontal metal coil orientation is often preferred because the metal coil can be transported through the manufacturing and fabricating environments using large overhead cranes, which traverse the plant on overhead rails. The overhead crane has a large hook, or xe2x80x9cCxe2x80x9d hook, which is placed through the eye of the metal coil. The crane is then able to lift the metal coil, move along the track and lower the metal coil at its next desired location.
A problem encountered with metal coils which are exposed to the environment is corrosion. Corrosion degrades the quality and color of the metal. One method used to prevent corrosion is to wrap the metal coil in a plastic film which contains a vapor phase corrosion inhibitor (VPCI) material. U.S. Pat. No. 5,139,700 to Miksic et al. describes commonly used VPCI materials and is incorporated herein by reference. The metal coil is wrapped or enclosed in the VPCI impregnated plastic film such that the air enclosed in and around the metal coil is isolated from the outside of the plastic wrap enclosure. The VPCI then saturates the enclosed air and forms a layer on the surface of the metal coil. This layer prevents corrosion on the surface of the metal. Methods of enclosing metals and metal components as described above are disclosed in U.S. Pat. No. 5,937,618 to Chandler; U.S. Pat. No. 5,855,975 to Miksic et al.; and U.S. Pat. No. 5,715,945 to Chandler, all of which are incorporated herein by reference.
A significant shortcoming of the above-described wrapping and enclosure methods for protecting metal coils is that the metal coil can only be transported in the less desired eye to the sky orientation. This is because, in the eye horizontal orientation, the use of a C hook would puncture the plastic wrapping or enclosure, allowing the VPCI to escape to the atmosphere and allowing moisture to come in contact with the metal coil, eventually leading to corrosion.
Thus, there is an established need to provide a means to wrap or encase metal coils to prevent corrosion such that the metal coils may be transported in the eye horizontal orientation.
The present invention relates to an apparatus and method for enclosing and protecting a metal coil in VPCI impregnated materials such that they can be transported in an eye horizontal orientation.
The apparatus for protecting coiled metal of the present invention includes a metal coil that has an eye at its center and a vapor phase corrosion inhibitor (VPCI) impregnated material, which completely encloses an outer surface of the metal coil. A core extends along the length of the eye and has a first end and a second end. A first wing, having a collar that inserts into the first end of the core and wing members, is aligned next to the VPCI impregnated material. A second wing, having a collar that inserts into the second end of the core and wing members, is aligned next to the VPCI material.
The method for protecting coiled metal of the present invention is applied to a metal coil which has an eye, an inner surface, a first side, a second side and an outer surface. In the method, the metal coil is wrapped with a vapor phase corrosion inhibitor (VPCI) impregnated material such that the outer surface, first side and second side of the metal coil are encased by the VPCI impregnated material. A core having a first end, a second end, an inner surface and an outer surface is inserted into the eye of the metal coil. A collar of a first wing is placed within the first end and against the inner surface of the core, and wing members of the first wing are placed against the VPCI impregnated material. A collar of a second wing is placed within the second end of the core and against the inner surface of the core, and wing members of the second wing are placed against the VPCI impregnated material.